Wafer-level method of fabricating a contact pad copper cap layer

A structure and a fabrication method for metallurgical connections between solder bumps (509) and contact pads (501) positioned on integrated circuits (IC) having copper interconnecting metallization protected by an overcoat (503). The structure comprises a portion of the copper metallization exposed by a window (501a) in the overcoat, where the exposed copper has a chemically and plasma cleaned surface. A copper layer (507) is directly positioned on the clean copper metallization, and patterned; the resulting metal structure has an electrical (and thermal) conductivity about equal to the conductivity of pure copper. The copper layer overlaps the perimeter of the overcoat window and a copper stud (508) is positioned on said copper layer. Finally, one of the solder bumps (509) is bonded to the copper stud.